An electronic on-board recorder (EOBR) is an electronic device, being one type of mobile data terminal (MDT), attached to a commercial motor vehicle, which is used to record the amount of time a vehicle is being driven. The driving hours of commercial drivers (truck and bus drivers) are regulated by a set of rules known as the hours of service (HOS). HOS rules are intended to prevent driver fatigue, by limiting the amount of time drivers spend operating commercial vehicles. An automatic on-board recorder (AOBR) is another type of MDT that may be used, which is comparable to an EOBR in terms of capabilities. Hereinafter, for the purpose of brevity, the designation MDT will be employed to mean either an EOBR or AOBR.
In order for the MDT to be considered compliant and useable as required by jurisdictional regulations, the device must be integrally synchronized with the operation of the vehicle so that the device is able to detect when the vehicle is in motion (in other words, be able to track all vehicle motion), and collect odometer data. The MDT must also be able to detect when integral synchronization is compromised (i.e. disconnected), report and record when integral synchronization is compromised, and report and record when integral synchronization is restored. The two reasons for reporting disconnections and reconnections are to inform the driver if/when something fails in the MDT so that appropriate backup actions can be taken, and to inform an inspector when a driver intentionally attempted to hide driving activity (in other words, when the MDT was unable to monitor motion and indicate possible tampering and ghost trip attempts).
FIG. 1 illustrates a typical prior art vehicle tracking and monitoring system, generally designated 10. The system 10 meets the aforementioned integrally synchronization requirements with respect to operation of a given vehicle, that is, it can detect when the vehicle is in motion and collect odometer data. In the system 10, a software application (not shown) running in a user interface (not shown) in a MDT 12 (either in the form of an EOBR or AOBR device) monitors driver status reported through the user interface and also vehicle state data as reported by a vehicle tracking device (VTD) 14. The MDT 12 records changes in these monitored values as a driver's record of duty status (RODS), which is recorded in a data store 12A of the MDT 12 for future display to an inspector. The VTD 14 is interfaced with a vehicle information bus (VIB) 16 and a global positioning system (GPS) receiver 18 by a combination of hardware and firmware (not shown). The VIB 16 is an information network installed in the vehicle, for example by the vehicle manufacturer, which provides access to operational and diagnostic information over standard protocols, such as OBDII, JBUS or CAN BUS. The VTD 14 is a known device commonly referred to as a locator device, which is described in detail in U.S. Pat. No. 7,538,667 issued to same assignee as the subject application. The disclosure of said patent is incorporated herein by reference thereto.
GPS satellites broadcast signals that can be received and processed by the system 10 to derive latitude, longitude and current time with respect to the location of the vehicle. The GPS receiver 18 includes a processor (not shown) that can receive and interpret the signals broadcasted from the GPS satellites and provide the location (latitude and longitude) of the vehicle and current time. Data processor hardware and firmware of the VTD 14 monitors and interprets signals and protocols from the VIB 16 and the GPS receiver 18 in order to obtain data with respect to the given vehicle such as current Speed, Odometer, Location and Time for use by the MDT 12. Power is drawn from a vehicle battery 20 for operation of the system 10.
Constant power connections via PWR inputs and ignition-switched power connections via IGN SENSE inputs on both the MDT 12 and VTD 14 are made with the vehicle battery 20. These constant power connections from the vehicle battery 20 to the MDT 12 and VTD 14 are made through respective protective fuses 22, 24. These ignition-switched power connections from the vehicle battery 20 to the MDT 12 and VTD 14 are made through respective protective fuses 26, 28. An ignition switch 30 is operated by the driver of the given vehicle to start and stop the vehicle engine or motor.
In order to understand where potential problems can arise in detecting the connectivity status of the MDT 12, first the operation of the system 10 during its Start Up, Monitoring and Shut Down phase need to be described. It is during these phases when disconnection of connectivity, whether intentional or not, is likely to occur.
The Start Up phase of the system 10 has a VTD startup mode and a MDT startup mode. In the VTD startup mode, the driver activates the ignition switch 30 to start the engine. As a consequence, the VTD 14 detects power on its IGN SENSE input, wakes up from its low power consumption mode, powers up the GPS receiver 18, and initializes itself. If the VTD 14 does not have an internal battery (which is optional) or at this time its internal battery is exhausted, then the VTD 14 will not have a current time and must initialize its clock from the GPS receiver 18. Even with the GPS receiver 18 at power, it can still require as much as ten seconds for the GPS receiver 18 to first acquire satellite signals and resolve a location and current time. In the MDT startup mode, the MDT 12 detects the same ignition on event via its IGN SENSE input, wakes up from its low power consumption mode, and displays a user interface to the driver.
The Monitoring phase of the system 10 has a VTD monitoring mode and a MDT monitoring mode. Once the VTD 14 is powered up and initialized, it starts monitoring vehicle activities. In the VTD monitoring mode, regularly polling of the GPS receiver 18 and VIB 16 occur to obtain current values for Speed, Odometer, Time and Location (Latitude and Longitude). Changes in the Speed are further interpreted by the VTD 14 resulting in a Vehicle State with values of Going or Stopped. In the MDT monitoring mode, after wake-up the MDT 12 polls the VTD 14 for current Time, Location, Vehicle State and Odometer data. When the Vehicle State changes from Stopped to Going, a RODS is recorded in the data store 12A of the MDT 12 indicating the driver has started Driving. When the Vehicle State changes from Going to Stopped, a RODS is recorded in the data store 12A indicating the driver is On Duty Not Driving. Every RODS is recorded in the data store 12A with Time, Location and Odometer values most recently obtained from the VTD 14. Additional duty status values, not relevant to this discussion, may be inputted by the driver and recorded in the data store 12A.
The Shut Down phase of the system 10 has a VTD shutdown mode and a MDT shutdown mode. In the VTD shutdown mode, the driver deactivates the ignition switch 30 to shutoff the engine. As a consequence, the VTD 14 detects power loss on its IGN SENSE input and proceeds to shutdown with a return to its low power consumption mode. A delay exists between detection of the ignition off event and the shutdown but in the end the VTD 14 stops polling the VIB 16 and GPS receiver 18, powers down the GPS receiver 18, stops responding to MDT data requests and goes to sleep. In the MDT shutdown mode, the MDT 12 detects the same ignition off event via its IGN SENSE input and initiates a similar shutdown sequence to return to its low power consumption mode. A delay exists between detection of the ignition off event and the shutdown but in the end the MDT 12 stops polling the VTD 14 and goes to sleep.
FIG. 2 illustrates a modification of the prior art vehicle tracking and monitoring system of FIG. 1, now generally designated 10A. The system 10A is modified to incorporate a hardware based disconnection monitor in the form of a specialized interconnection cabling 32A of the connection 32. The cabling 32A is used in conjunction with a digital input on the VTD 14 to detect disconnections between the MDT 12 and the VTD 14. The cabling 32A includes an additional wire 34 carrying power to a digital input of the VDT 14 from the constant battery power connection to the PWR input of the MDT 12. The digital input of the VDT 14 is held High (positive voltage) while the MDT 12 is powered and connected. The digital input of the VDT 14 drops Low (zero voltage) when either the MDT 12 is disconnected or the MDT power is removed.
When the MDT constant battery power to the VTD 14 via the wire 34 of the cabling 32A is cut by removal of the fuse 22, the VTD 14 detects the loss of power on the digital input and caches a disconnection event. When MDT constant battery power to the VTD 14 via the wire 34 of the cabling 32 is restored by replacement of the fuse 22, the VTD 14 detects the power on the digital input and caches a reconnection event. These events are communicated to the MDT 12 and recorded in the data store 12A of the MDT 12 as Device Disconnection and Reconnection records the next time the MDT 12 establishes communications with the VTD 14. When the cabling 32A is disconnected at either end, the VTD 14 detects loss of power on the digital input and caches a disconnection event. When the cabling 32A is reconnected, the VTD 14 detects power on the digital input and caches a reconnection event. These events are communicated to the MDT 12 and recorded in the data store 12A as Device Disconnection and Reconnection records the next time the MDT 12 establishes communications with the VTD 14.
However, the modified system 10A is not able to detect when the MDT 12 ignition sense is affected by removal of the fuse 26. In this case the MDT 12 will remain in power save mode and not track or record changes in vehicle state. Also, the modified system 10A is not able to detect when the VTD power fuse 24 or ignition fuse 28 are affected. In these cases the VTD 14 is powered off or asleep and the MDT 12 will not be able to track vehicle state changes. Additional features are necessary within the MDT 12 to record when communications fail to the VTD 14. Further, the modified system 10A is not able to detect disconnections of the connection 36 between the VIB 16 and the VTD 14. In these cases the vehicle will appear to not be moving when it is. GPS data could be used in conjunction to detect vehicle motion but GPS jamming will compromise that solution as well.
FIG. 3 illustrates another modification of the prior art vehicle tracking and monitoring system of FIG. 1, now generally designated 10B. The system 10B is modified to incorporate a time based polling disconnection monitor 38 in the form of a software module within the MDT 12 to store the time of each poll response received from the VTD 14. This is called Time of Last Contact. Polling occurs at a fixed frequency so there is an expected period between polls. The duration between polls is compared to the expected poll period. When the duration exceeds the expected period, the polling monitor 38 can assume that a disconnection occurred at some time between the Time of Last Contact and the current poll attempt and record a Device Reconnection record in the data store 12A of the MDT 12 that also reports when the last contact was.
When the MDT power at the PWR input or the ignition sense at the IGN SENSE input of the MDT 12 is affected by removal of either the fuse 22 or fuse 26, the MDT 12 and its polling monitor 38 are not operational. No detection can occur at that time, not until the affected power or ignition sense is restored and the polling sensor of the monitor 38 detects a lengthy period of time elapsed since the Time of Last Contact and produces a Device Reconnection record. This requires use of non-volatile ram to store the Time of Last Contact. When the cabling 32 (see FIG. 3) between the MDT 12 and VTD 14 is disconnected, the polling sensor of the monitor 38 will quickly detect a lengthy period of time since Time of Last Contact and produce a Device Disconnection record. When the cabling 32 is restored, the polling sensor of the monitor 38 is able to detect this as well and produce the Device Reconnection record. When the VTD power at the PWR input or the ignition sense at the IGN SENSE input of the VTD 14 is affected by removal of either the fuse 24 or fuse 28, the polling sensor of the monitor 38 will quickly detect a lengthy period of time since Time of Last Contact and produce a Device Disconnection record. Restoring the power or ignition sense will also be detected by the polling sensor and a Device Reconnection record produced.
However, the modified system 10B is not able to detect disconnections of the connection 36 of the VIB 16 with the VTD 14 and in these cases the vehicle will appear to not be moving even when it is. Additional logic is necessary in the VTD 14 to use GPS data in conjunction with VIB motions to detect vehicle motion but methods of GPS jamming will compromise that solution as well. Furthermore, the modified system 10B will detect natural power cycles as disconnection and reconnection events which when examined after the fact will make it extremely difficult to distinguish a tampering disconnection and reconnection sequence from a natural power cycle disconnection and reconnection sequence.
There is therefore a need for an innovation that solves the aforementioned problems of detecting connectivity of the MDT to the vehicle without producing false events that would add noise and make it difficult for an inspector to identify the real tampering and ghost trips.